Title

Microstructure Characterization Of As-Fabricated And 475 °C Annealed U-7 Wt.% Mo Dispersion Fuel In Al-Si Alloy Matrix

Keywords

Diffusion reaction; Interface; Nuclear fuels; TEM; U(Mo)

Abstract

High-density uranium (U) alloys with an increased concentration of U are being examined for the development of research and test reactors with low enriched metallic fuels. The U-Mo fuel alloy dispersed in Al-Si alloy has attracted particular interest for this application. This paper reports our detailed characterization results of as-fabricated and annealed (475 °C for 4 h) U-Mo dispersion fuels in Al-Si matrix with a Si concentration of 2 and 5 wt.%, named as "As2Si", "As5Si", "An2Si", "An5Si" accordingly. Techniques employed for the characterization include scanning electron microscopy and transmission electron microscopy with specimen prepared by focused ion beam in situ lift-out. Fuel plates with Al-5 wt.% Si matrix consistently yielded thicker interaction layers developed between U-Mo particles and Al-Si matrix, than those with Al-2 wt.% Si matrix, given the same processing parameters. A single layer of interaction zone was observed in as-fabricated samples (i.e., "As2Si", "As5Si"), and this layer mainly consisted of U3Si3Al2 phase. The annealed samples contained a two-layered interaction zone, with a Si-rich layer near the U-Mo side, and an Al-rich layer near the Al-Si matrix side. The U 3Si5 appeared as the main phase in the Si-rich layer in "An2Si" sample, while both U3Si5 and U 3Si3Al2 were identified in sample "An5Si". The Al-rich layer in sample "An2Si" was amorphous, whereas that in sample "An5Si" mostly consisted of crystalline U(Al,Si)3, along with a small fraction of U(Al,Si)4 and U6Mo4Al43 phases. The influence of Si on the diffusion and reaction in the development of interaction layers in U(Mo)/Al(Si) is discussed in the light of growth-controlling mechanisms and irradiation performance. © 2011 Elsevier B.V.

Publication Date

9-29-2011

Publication Title

Journal of Alloys and Compounds

Volume

509

Issue

39

Number of Pages

9487-9496

Document Type

Article

Personal Identifier

scopus

DOI Link

https://doi.org/10.1016/j.jallcom.2011.07.048

Socpus ID

81155160965 (Scopus)

Source API URL

https://api.elsevier.com/content/abstract/scopus_id/81155160965

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